NBME 21

nbme21/Block 2/Question#31

A 37-year-old man is brought to the emergency ...

Intercostal

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submitted by hayayah(54),

With this question, I think they want you to recognize that the patient isn't having chest pain related to the heart. They emphasize several rib fractures and a pneumothorax but don't indicate any heart damage (lack of adventitious sounds = no pulmonary edema indicated or a lung issue related to heart problem).

The pericarditis is what's innervated by the phrenic n. Seeing as how his heart is fine, the fractured ribs are probably what are causing him pain via the intercostal nerves.


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submitted by vlodkadrinker(1),

why? like does my med school suck or am I just that dumb cuz we never learned anything like this

sklawpirt  I think its just that the patient is CONSCIOUSLY experiencing chest pain. Because he is consciously feeling the pain and would be able to directly point to it (and that it is not referred visceral pain) it has to be a somatic afferent nerve fiber. This narrows it down exclusively to the intercostal nerve exc;usively. https://en.wikipedia.org/wiki/Intercostal_nerves IMportant to the patients "right sided chest pain" is his history of MVA and x-ray confirming multiple rib fractures. I think this is correct? Does that make sense ? All of the other choices do not carry SA fibers in that area